Gift: eternal rainbow

Haruhiko Amaumi is a high school student at Shimano Academy in the town of Narasakicho, a place perpetually watched over by a mysterious rainbow. This celestial phenomenon is tied to the "Gift," a magical, once-in-a-lifetime wish shared between two people. During his childhood, Haruhiko was inseparable from his friend Kirino until Riko joined his family as an adopted sister. The two formed a deep bond but were eventually separated when Haruhiko’s father could no longer support them both. Years later, Riko returns to Narasakicho and enrolls at Shimano Academy alongside Haruhiko and Kirino. The series explores the evolving relationships among these central characters while gradually uncovering the secrets behind the Gift and the eternal rainbow.